U.S. patent application number 15/803467 was filed with the patent office on 2018-05-10 for apparatus and respective method for communicating with a transponder and system for communicating.
The applicant listed for this patent is Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.. Invention is credited to Frederic MEYER, Philip SCHMIDT, Gerd VOM BOEGEL.
Application Number | 20180129839 15/803467 |
Document ID | / |
Family ID | 62003239 |
Filed Date | 2018-05-10 |
United States Patent
Application |
20180129839 |
Kind Code |
A1 |
SCHMIDT; Philip ; et
al. |
May 10, 2018 |
APPARATUS AND RESPECTIVE METHOD FOR COMMUNICATING WITH A
TRANSPONDER AND SYSTEM FOR COMMUNICATING
Abstract
The invention relates to an apparatus for communicating with a
transponder. The apparatus includes a transmit apparatus, a receive
apparatus and an evaluation apparatus. The transmit apparatus
transmits a transmit signal to the transponder. Based on a signal
emitted by the transponder, the receive apparatus receives a
receive signal. Based on the transmit signal and/or a signal
portion, the evaluation apparatus evaluates the receive signal with
respect to data errors. Further, the invention relates to a
respective method as well as to a system for communicating.
Inventors: |
SCHMIDT; Philip; (Attendorn,
DE) ; VOM BOEGEL; Gerd; (Wuelfrath, DE) ;
MEYER; Frederic; (Erndtebrueck, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung
e.V. |
Munich |
|
DE |
|
|
Family ID: |
62003239 |
Appl. No.: |
15/803467 |
Filed: |
November 3, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04L 7/042 20130101;
H04L 27/2273 20130101; G06K 7/10118 20130101; G06K 7/10346
20130101; G01S 13/765 20130101; G06K 7/0008 20130101 |
International
Class: |
G06K 7/10 20060101
G06K007/10; G06K 7/00 20060101 G06K007/00; H04L 27/227 20060101
H04L027/227 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 4, 2016 |
DE |
10 2016 221 660.0 |
Claims
1. Apparatus for communicating with a transponder, wherein the
apparatus comprises a transmit apparatus, a receive apparatus and
an evaluation apparatus, wherein the transmit apparatus is
configured to emit a transmit signal to the transponder, wherein
the receive apparatus is configured to receive a receive signal
based on a signal emitted by the transponder, and wherein the
evaluation apparatus is configured to evaluate the receive signal
with respect to data errors based on the transmit signal and/or a
signal portion.
2. Apparatus according to claim 1, wherein the evaluation apparatus
is configured to evaluate the receive signal with respect to data
errors using the transmit signal and/or a signal portion.
3. Apparatus according to claim 1, wherein the signal emitted by
the transponder is based on the transmit signal and the data signal
of the transponder.
4. Apparatus according to claim 1, wherein the transmit signal
comprises two independent signal portions.
5. Apparatus according to claim 4, wherein the signal portions
originate from two different signal sources.
6. Apparatus according to claim 1, wherein the evaluation apparatus
is configured to provide a data signal of the transponder based on
the receive signal.
7. Apparatus according to claim 1, wherein a data rate of the
transmit signal is predetermined such that the data rate of the
transmit signal is greater than a data rate of a data signal of the
transponder.
8. Apparatus according to claim 1, wherein the evaluation device of
the evaluation apparatus is configured to synchronize the receive
signal with a synchronization signal and wherein the
synchronization signal is predetermined based on the transmit
signal.
9. Apparatus according to claim 1, wherein the transmit apparatus
is configured to emit the transmit signal multiple times and/or
across a predetermined transmit time period.
10. Apparatus according to claim 1, wherein the apparatus is
configured as RFID reader, and wherein the transponder is an RFID
transponder.
11. System for communicating, wherein the system comprises an
apparatus for communicating with a transponder and a transponder,
wherein the apparatus comprises a transmit apparatus, a receive
apparatus and an evaluation apparatus, wherein the transmit
apparatus is configured to emit a transmit signal to the
transponder, wherein the receive apparatus is configured to receive
a receive signal based on a signal emitted by the transponder,
wherein the evaluation apparatus is configured to evaluate the
receive signal with respect to data errors based on the transmit
signal and/or a signal portion, wherein the transponder comprises a
transponder receive apparatus and a transponder transmit apparatus,
wherein the transponder receive apparatus is configured to receive
a signal from the apparatus, and wherein the transponder transmit
apparatus is configured to emit a signal based on the received
signal and the data signal to the apparatus.
12. System according to claim 11, wherein the evaluation apparatus
is configured to evaluate the receive signal with respect to data
errors using the transmit signal and/or a signal portion,
13. System according to claim 11, wherein the transponder is
configured such that the signal emitted by the transponder is based
on a modulation of the transmit signal with a data signal of the
transponder.
14. Method for communicating with a transponder, wherein the
transmit signal is emitted to the transponder, wherein a receive
signal depending on a signal emitted by the transponder is
received, and wherein the receive signal is evaluated with respect
to data errors based on the transmit signal and/or a signal
portion.
15. Method according to claim 14, wherein the receive signal is
evaluated with respect to data errors using the transmit signal
and/or a signal portion.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from German Patent
Application No. 10 2016 221 660.0, which was filed on Nov. 4, 2016,
and is incorporated herein in its entirety by reference.
[0002] The invention relates to an apparatus for communicating with
a transponder as well as to a system for communicating. Further,
the invention relates to a method for communicating with a
transponder.
BACKGROUND OF THE INVENTION
[0003] If data are transmitted in a contactless and in particular
in a wireless manner, e.g., via electromagnetic waves,
interferences that can possibly even influence or change the
transmitted data can be coupled in by noise or by crosstalk of
other signals. For ensuring secure data transmission, it is known
to transmit the data in a redundant manner, for example by
transmitting, e.g., checksums together with the actual data. If the
received data deviate from the checksum, obviously, an error has
occurred during transmission. Here, the signals are transmitted
from a transponder to a receiver or generally an apparatus for
communicating with a transponder.
[0004] In conventional technology, it is known to provide objects
with RFID transponders (RFID=radio frequency identification) or
also RFID tags as an example of the above-stated transponders. RFID
readers can read out identification data from the RFID transponders
or data (for example measurement data) are transmitted from an
object connected to the transponder (e.g., a measuring device or
sensor) to the reader.
[0005] The more and more frequently used high-frequency RFID
transponders of conventional technology are typically passive and
are excited and activated, respectively, by a high-frequency
electromagnetic field. Generally, these RFID transponders have only
little energy or no individual energy resources at all. Thus, the
transponder uses the transmit signal from the reader and transmits,
in response to the excitation, a modulated signal back to the
reader. In most cases, the modulated signal is a backscatter
signal, so that the signal emitted by the transponder results from
a modulation of the transmit signal of the reader received by the
transponder with a data signal of the transponder. By means of the
data signal, this response signal includes information from the
transponder that can be evaluated by the reader.
[0006] Thus, data integrity, i.e., secure and error-free
transmission of the data signal is to be ensured, if in RFID
transponders, according to conventional technology, data
originating from the transponder have to be transmitted in a
redundant manner. However, the increased data volume is
disadvantageous, in particular in the example of the RFID
transponders having limited energy resources.
SUMMARY
[0007] According to an embodiment, an apparatus for communicating
with a transponder may have a transmit apparatus, a receive
apparatus and an evaluation apparatus, wherein the transmit
apparatus is configured to emit a transmit signal to the
transponder, wherein the receive apparatus is configured to receive
a receive signal based on a signal emitted by the transponder, and
wherein the evaluation apparatus is configured to evaluate the
receive signal with respect to data errors based on the transmit
signal and/or a signal portion.
[0008] According to another embodiment, a system for communicating
may have an apparatus for communicating with a transponder and a
transponder, wherein the apparatus includes a transmit apparatus, a
receive apparatus and an evaluation apparatus, wherein the transmit
apparatus is configured to emit a transmit signal to the
transponder, wherein the receive apparatus is configured to receive
a receive signal based on a signal emitted by the transponder,
wherein the evaluation apparatus is configured to evaluate the
receive signal with respect to data errors based on the transmit
signal and/or a signal portion, wherein the transponder includes a
transponder receive apparatus and a transponder transmit apparatus,
wherein the transponder receive apparatus is configured to receive
a signal from the apparatus, and wherein the transponder transmit
apparatus is configured to emit a signal based on the received
signal and the data signal to the apparatus.
[0009] Another embodiment may have a method for communicating with
a transponder, wherein the transmit signal is emitted to the
transponder, wherein a receive signal depending on a signal emitted
by the transponder is received, and wherein the receive signal is
evaluated with respect to data errors based on the transmit signal
and/or a signal portion.
[0010] The invention solves the object by an apparatus for
communicating (also unidirectional or bidirectional transmission of
data) with a transponder. The apparatus comprises a transmit
apparatus, a receive apparatus and an evaluation apparatus. The
transmit apparatus is configured to emit a transmit signal to the
transponder. The receive apparatus is configured to receive a
receive signal based on a signal emitted by the transponder.
Finally, the evaluation apparatus is configured to evaluate the
receive signal with respect to data errors based on the transmit
signal and/or a signal portion.
[0011] The apparatus emits a transmit signal that results, in one
configuration, from two signal portions, to the transponder, i.e.,
in its direction and/or at a frequency that can be received by the
transponder and/or with a transmit power sufficient for reaching
the transponder. In one configuration, two signals are combined,
e.g., modulated together for this.
[0012] The transmit signal is received by the transponder and is
returned to the apparatus, e.g. by backscattering. In one
configuration, the transponder modulates in particular the transmit
signal, such that the same carries data, in particular a data
signal, of the transponder. Subsequently, the signal of the
transponder is received by the receive apparatus of the apparatus,
after the same has passed the space between the apparatus and the
transponder and after interferences or superpositions with other
signals have possibly taken place.
[0013] Thereupon, an evaluation apparatus evaluates the receive
signal based on the transmit signal and at least one signal portion
(in one configuration, this relates to data allowing a description
of the transmitted signal) of the transmit signal, respectively. In
that the receive signal results from a modulation of the transmit
signal with a data signal of the transponder in one configuration,
the receive signal comprises the transmit signal at least partly in
one configuration.
[0014] Thus, in one configuration, the evaluation apparatus
determines whether any deviations with respect to the transmit
signal and to one of the signal portions--at least two in one
configuration--of the transmit signal, respectively, exist in the
receive signal. If, for example, the receive signal would have to
carry a signal portion of the transmit signal, but differences as
regards to shape, frequency or wave form in general occur (e.g.,
due to interruptions), this means that the signal from the
transponder to the apparatus has been damaged and that the data
signal extracted from the receive signal can be erroneous. Thus,
when evaluating the receive signal, the transmit signal enables the
detection of data errors in the receive signal. Thus, it can be
detected whether the transmission of the data had been erroneous.
Thus, the evaluation apparatus is configured to determine, based on
the transmit signal and a signal portion of the transmit signal,
respectively, whether a data signal of the transmitter had been
transmitted correctly or whether interferences can be detected.
[0015] According to one configuration, the transmit signal
comprises two different signal portions.
[0016] In one configuration, communication is carried out in
particular with a transponder that emits signals according to the
backscatter principle. Thus, coupling by modulated backscattering
exists between the apparatus and the transponder.
[0017] According to one configuration, the signal emitted by the
transponder is based on the transmit signal and a data signal of
the transponder.
[0018] In one configuration, the receive signal is based on the
fact that the transponder modulates a data signal onto the transmit
signal received by the same.
[0019] The following configurations relate to the transmit signal
and the two signal portions which result in the transmit signal
according to one configuration.
[0020] In one configuration, it is provided that the signal
portions originate from two independent signal sources. Thus, one
configuration provides that the apparatus comprises two such signal
sources.
[0021] In one configuration, a first signal portion is implemented
as carrier. Additionally or alternatively, in one configuration, a
second signal portion is configured such that the same serves for
carrier suppression.
[0022] In a further configuration, it is intended that data, in
particular in the form of a data signal, are modulated onto a first
signal portion.
[0023] One configuration is that a first signal portion is
configured as amplitude-modulated signal. This has the advantage
that demodulation of an amplitude-modulated signal can be realized
on the transponder side in a very good and energy-efficient
manner.
[0024] According to one configuration, a first signal portion can
consists of a temporarily repeating information sequence. In an
additional or alternative configuration, a second signal portion
can serve synchronization purposes.
[0025] According to a configuration, the second signal portion
serves for the transmission of information for controlling carrier
suppression.
[0026] In one configuration, it is intended that a second signal
portion is configured as phase-modulated or frequency-modulated
signal or is configured as a signal according to orthogonal
frequency-division multiplexing (OFDM).
[0027] According to a configuration, a signal portion of the
transmit signal which, in one configuration, does in particular not
transmit any data to the transponder is phase-modulated. Phase
modulation has the advantage that synchronization of the receive
signal with the transmit signal and the second signal portion,
respectively, can be realized via the phase. This reduces computing
power, for example compared to frequency modulation.
[0028] In one configuration, the transmit signal emitted by the
apparatus having the transmit apparatus (possible designations for
the apparatus are generally also base station or reader), in
particular to the transponder, consists of two parts: in one
configuration this is, on the one hand, an amplitude-modulated part
(and transmit part, respectively) that transmits data in the
direction of the transponder. On the other hand, this is a
phase-modulated part (and signal portion, respectively) that is not
relevant for the transponder and also carries no data for the
transponder but that is used for carrier suppression after
backscatter modulation of the transmit signal in the base station
(i.e., the apparatus for communicating).
[0029] One configuration is that the signal portions of the
transmit signal have the same data rate or different data
rates.
[0030] In one configuration, it is intended that the signal
portions are incoherent.
[0031] One configuration includes that the evaluation apparatus is
configured to provide a data signal of the transponder based on the
receive signal. In this configuration, the evaluation apparatus
extracts a data signal of the transponder from a receive signal,
e.g., by demodulation by using the transmit signal.
[0032] According to a configuration, synchronization of transmit
signal and receive signal is performed without demodulation of the
two signals.
[0033] In one configuration, it is intended that the data rate of
the transmit signal is predetermined such that the data rate of the
transmit signal is greater than a data rate of a data signal of the
transponder that is to be expected in one configuration. If the
transmit signal comprises two signal portions, the transmit signal
will also have two different data rates in one configuration.
[0034] If the transmit signal comprises two signal portions (here
referred to as first and second signal portions, respectively), one
configuration provides that a data rate of a second signal portion
of the transmit signal is predetermined such that the data rate of
the second signal portion is greater than a data rate of a data
signal of the transponder.
[0035] Thus, in this configuration, the data rate of a data signal
of the transponder is lower than the data rate of the transmit
signal. By predetermining the data rates, it is quasi determined
that the data signal having a lower data frequency is superposed by
a signal, namely the transmit signal or a signal portion of the
transmit signal, having a higher data frequency in the frequency
domain. In other words, the transmit signal and a signal portion of
the transmit signal, respectively, is "mounted" on the data signal
of the transponder in the frequency domain.
[0036] According to one configuration, the evaluation apparatus is
configured to synchronize the receive signal with a synchronization
signal.
[0037] Here, in one configuration, the synchronization signal is
predetermined based on the transmit signal and in one configuration
the same can be identical to the transmit signal.
[0038] In a further configuration, the evaluation apparatus is
configured to synchronize the receive signal for demodulation with
regard to frequency and/or phase.
[0039] In one configuration, the transmit apparatus is configured
to emit the transmit signal multiples times and/or across a
predetermined transmit time period. This configuration enables, in
particular in a RFID transponder, constant energy supply of the
same. Further, this configuration has the effect that the transmit
signal of the apparatus interacts with the signal emitted by the
transponder, such that superposition on the transmission path
results. The transmit time period and the time across which
multiple emission of the transmit signal extends, respectively, is,
in one configuration, so long that the transmit signal can
influence and possibly superimpose the signal transmitted by the
transponder, i.e. in one configuration the modulated backscatter
signal.
[0040] In one configuration, the apparatus enables multi-receiver
capability, since no limitation exists in point-to-multipoint
transmission (broadcast method). Thus, in one configuration, by
announcing the selected encoding to specific receivers and
transponders, groups are formed that are enabled to receive the
transmit signal of the apparatus. This results in a simple
selection of desired transponders from a greater number of existing
receivers. This is also based on the fact that a signal portion of
the transmit signal can serve as key.
[0041] According to one configuration, the apparatus is configured
as RFID reader and the transponder is an RFID transponder.
[0042] Further, the invention relates to a transponder that
receives signals, modulates a data signal and emits the received
signal modulated with the data signal again. Here, in particular,
backscatter modulation takes place. The signal transmitted by the
transponder can generally also be referred to as response signal of
the transponder.
[0043] Further, the invention solves the object by a system for
communicating. Here, communicating relates in particular to the
communication between an apparatus for communication (as described,
for example, exemplarily in the above configurations) and a
transponder.
[0044] The system for communicating comprises an apparatus for
communicating with a transponder (in one configuration, the
apparatus is an RFID reader) and such a transponder (for example an
RFID transponder).
[0045] The apparatus comprises a transmit apparatus, a receive
apparatus and an evaluation apparatus. The transmit apparatus is
configured to emit a transmit signal to the transponder. The
receive apparatus is configured to receive a receive signal based
on a signal emitted by the transponder. Finally, the evaluation
apparatus is configured to evaluate the receive signal with respect
to data errors based on the transmit signal and/or a signal
portion.
[0046] The transponder comprises a transponder receive apparatus
and a transponder transmit apparatus. The transponder receive
apparatus is configured to receive a signal from the above-stated
apparatus. The transponder transmit apparatus is configured to emit
a signal based on the received signal and on a data signal to the
apparatus, quasi as response signal.
[0047] In this system, the apparatus transmits a transmit signal by
its transmit apparatus, which is received by the transponder by its
transponder receive apparatus. With its transponder transmit
apparatus, the transponder transmits a (response) signal to the
apparatus which is based on the received signal, i.e. the received
transmit signal of the apparatus and a data signal. Thereupon, the
apparatus receives a receive signal with its receive apparatus that
is based on the signal emitted by the transponder and evaluates the
same with respect to data errors. Thus, the apparatus examines
whether the signal transmitted by the transponder has arrived in an
error-free manner. The transmit signal and at least one signal
portion of the transmit signal, respectively, is used for the
evaluation.
[0048] According to an optional configuration, the transmit signal
comprises at least two signal portions. In an alternative
configuration, the transmit signal does not have several signal
portions. In one configuration, the transmit signal is exclusively
phase-modulated. In this case, no data transmission in the
direction of the transponder takes place due to the non-existing
amplitude-modulated portion. Thus, the transponder can be
configured in a simpler way, such that, e.g. no receive apparatus
exists.
[0049] The apparatus for communicating with the transponder is
implemented according to one of the above configurations, such that
the above explanations also apply for the system. The same applies
vice-versa.
[0050] In one configuration, the transponder is configured such
that the signal emitted by the transponder is based on a modulation
of the transmit signal with a data signal of the transponder. Here,
the transponder performs a so-called backscatter modulation of the
signal received by the same (i.e. the transmit signal of the
apparatus for communication).
[0051] In one configuration, a data rate of the transmit signal is
predetermined to be greater than a data rate of the data signal of
the transponder. Here, in one configuration, a high-frequency
transmit signal can be modulated with a low-frequency data
signal.
[0052] According to one configuration, the transmit apparatus is
configured to emit the transmit signal multiple times and/or across
a predetermined transmit time period. By the continuous or repeated
emission of the transmit signal, it is possible that the signal
emitted by the transponder is superposed by the transmit
signal.
[0053] In one configuration, an analog carrier suppression method
is used.
[0054] According to one configuration, the apparatus is configured
as an RFID reader and the transponder is an RFID transponder.
[0055] Further, the invention solves the object by a method
allowing communication with a transponder. In one configuration,
communication relates to the fact that the transponder receives
data. In a further and purely optional configuration, data are also
transmitted to the transponder.
[0056] The method comprises at least the following steps: [0057] a
transmit signal is emitted to the transponder, [0058] a receive
signal depending on a signal emitted by the transponder is
received, and [0059] based on the transmit signal and/or signal
portion, the receive signal is evaluated with respect to data
errors.
[0060] In some configurations, the following results:
[0061] The transponder still receives the transmit signal.
Additionally, the transponder emits a signal that is based on the
signal received by the transponder and a data signal. The receive
signal is based on the signal transmitted by the transponder and
interferences possibly occurring on the transmission path of the
radio signals.
[0062] The above configurations of the apparatus for communication
can accordingly also be implemented by the method, such that the
above statements also apply accordingly for the method.
[0063] In detail, there are a plurality of options for configuring
and developing the inventive apparatus, the system and the method
further. In this regard, reference is made to the claims on the one
hand and to the following description of embodiments in connection
with the drawings on the other hand.
BRIEF DESCRIPTION OF THE DRAWINGS
[0064] Embodiments of the present invention will be detailed
subsequently referring to the appended drawings, in which:
[0065] FIG. 1 is a schematic illustration of a system having an
apparatus for communication and a transponder,
[0066] FIG. 2 is a schematic illustration of a further system
and
[0067] FIG. 3 is a schematic wave form of a signal received by the
apparatus.
DETAILED DESCRIPTION OF THE INVENTION
[0068] The apparatus 1 for wireless and radio-based communication
with a transponder and the transponder 2 form a system for
communication between the apparatus 1 and the transponder 2.
[0069] The apparatus 1 comprises a transmit apparatus 10 for
emitting a transmit signal Cs in the direction of the transponder
2. For the transmit signal Cs, the transmit apparatus 10 is
connected to two different signal sources 13, 14 each providing a
first signal portion As and a second signal portion Bs,
respectively. In an exemplary configuration, the second signal
portion Bs allows the transmission of data from the apparatus
1--alternative terms are, for example, depending on the
configuration, base station or reader--to the transponder 2. In a
different configuration, no data are transmitted, such that, for
example, no multi-part transmit signal Cs exists.
[0070] Thus, the transmit signal Cs comprises two different signal
portions As, Bs, such that the transmit signal Cs can also be
written as the sum of the two signal portions As, Bs: Cs=As+Bs.
However, the two signal portions relate merely to a possible
embodiment. In an alternative embodiment, the transmit signal is a
phase-modulated signal comprising only one signal portion.
[0071] For the transponder 2 to be supplied with sufficient energy
in the shown configuration, the transmit signal Cs is continuously
emitted.
[0072] Further, the apparatus 1 comprises a receive apparatus 11
for receiving signals that have been emitted by the transponder 2.
The received receive signal Fs depending on a signal Ds emitted by
the transponder 2 but possibly also from foreign radiations or also
crosstalk of the transmit signal Cs is processed by the evaluation
apparatus. Depending on the configuration, the evaluation apparatus
12 uses the transmit signal Cs or one of the two signal portions
As, Bs for evaluating the receive signal Fs.
[0073] The transponder 2 receives the transmit signal Cs with the
transponder receive apparatus 20 and thereby receives also the
energy of the same in the shown example. The received transmit
signal Cs is supplied to a modulator 22 which modulates the same
with a data signal Es and hence generates the signal Ds that is
emitted by the transponder transmit apparatus 21 to the apparatus
1. The data signal Es is supplied to the modulator 22 and relates,
for example, to identification data or measurement data.
[0074] Thus, the signal Ds to be transmitted by the transponder 2
is a result of the modulation of the transmit signal Cs with the
data signal Es of the transponder 2, such that the signal to be
transmitted Ds can be written as product of the transmit signal Cs
and the data signal referred to by Es: Ds=Es*Cs.
[0075] The receive signal Fs depends on the signal Ds emitted by
the transponder 2. Further, the receive signal Fs is possibly
dependent on crosstalk of the transmit signal Cs, such that the
receive signal Fs can also be described as a sum of signals:
Fs=Ds+Cs.
[0076] The (response) signal transmitted by the transponder 2, that
has been generated from the transmit signal Cs of the apparatus can
also be formulated as follows: Fs=Es*Cs+Cs.
[0077] Thus, in the normal case, the receive signal Fs comprises
the transmit signal Cs. In a further configuration, the receive
signal Fs includes at least one signal portion (As, Bs) of the
transmit signal Cs.
[0078] Thus, the evaluation apparatus 12 is configured such that
the same evaluates the receive signal Fs with regard to whether
deviations to the transmit signal Cs and the at least one signal
portion As, Bs, respectively, can be found. Thus, in one
configuration, the receive signal Fs is synchronized with a
synchronization signal Gs, wherein in one configuration the
synchronization signal Gs is equal to the transmit signal Cs. Thus,
in the latter configuration, the receive signal Fs is synchronized
with the transmit signal Cs.
[0079] Additionally, the evaluation apparatus 12 extracts the data
signal Es of the transponder 2 from the receive signal Fs, e.g. by
demodulation.
[0080] All in all, the evaluation apparatus 12 provides the data
signal Es of the transponder 2 as well as information on the data
integrity as a consequence of the wireless data communication.
[0081] FIG. 2 shows again a system that is based on the backscatter
modulation principle.
[0082] Here, the apparatus for communication 1 is configured as
reader and comprises a transmit apparatus 10, here referred to as
transmitter. This transmitter 10 receives the two independent
signal portions As and Bs and emits the transmit signal Cs which
consists of the two signal portions As and Bs. This is illustrated
by the formula: As+Bs=Cs. However, the formula relates only to the
illustrated exemplary configuration. Discovering errors during
transmission is possible independent of the fact whether the
transmit signal Cs consists of one or several parts.
[0083] In one configuration, the two signal portions As, Bs
originate from two different and independent signal sources and are
mixed with one another according to an arbitrarily predetermined
modulation type. In one configuration, the first signal portion As
represents the carrier onto which in a further configuration data
are modulated for transmission to the transponder 2. In one
configuration, the second signal portion Bs is an arbitrary signal
that is used for carrier suppression in one configuration.
[0084] The transmitter 10 transmits the transmit signal Cs to the
transponder receive apparatus 20 of the transponder 2. Here, the
transponder receive apparatus 20 is referred to as receiver.
[0085] Here, transmit apparatus 10 and the transponder receive
apparatus 20 are connected to one another via an air interface
across which the signals are transmitted.
[0086] Here, the transponder receive apparatus 20 is further
configured such that the same extracts a signal portion, here the
second signal portion Bs, from the received transmit signal Cs and
passes the same on to further components of the transponder 2 that
are not illustrated here.
[0087] The received transmit signal Cs reaches the transponder
transmit apparatus 21 from the receiver 20 of the transponder 2.
Here, the transponder transmit apparatus 21 is referred to as
transmitter and includes a backscatter modulator that modulates the
received transmit signal Cs with a data signal Es of the
transponder 2 and thereby generates the signal Ds which the
transponder 2 emits as response signal. Here, this response signal
Ds is described as multiplication of the data signal Es with the
received transmit signal Cs: Ds=Es*Cs.
[0088] The transmitter 21 of the transponder 2 transmits the
response signal Ds to the receive apparatus 11 of the apparatus 1.
Here, the receive apparatus 11 is referred to as receiver.
[0089] For supplying the transponder 2 with sufficient energy, in
the shown configuration, the apparatus 1 emits the transmit signal
Cs repeatedly and across a longer time period, respectively. This
results in crosstalk 3 of the transmit signal Cs on the response
signal Ds of the transponder 2 along the air interface.
[0090] Thus, the receive signal Fs received by the receiver 11 of
the apparatus 1 results as a sum of the response signal Ds and the
transmit signal Cs: Fs=Cs+Ds.
[0091] However, interferences by which the receive signal Fs
differs from the response signal Ds can still occur.
[0092] In a further configuration, no continuous emission or
repeated emission of the transmit signal Cs takes place, such that
the mentioned crosstalk 3 does not occur and the receive signal Fs
results directly from the signal Ds transmitted by the transponder
2 and possible interferences, respectively.
[0093] For detecting such errors or interferences, the receive
apparatus 11 is configured such that the same includes the
evaluation apparatus.
[0094] First, in the shown configuration, the receive signal Fs is
synchronized with regard to frequency and phases for achieving the
best possible demodulation. Subsequently, the synchronized receive
signal Fs is synchronized with a synchronization signal Gs that is
equal to the transmit signal Cs (illustrated by Gs=Cs). Further,
the receiver 11 also provides the data signal Es of the transponder
2, e.g. by a backscatter demodulator.
[0095] Thus, in the shown configuration, the receiver 11 of the
apparatus 1 determines, based on the transmit signal Cs, whether
the receive signal Fs comprises errors.
[0096] FIG. 3 shows a wave form of a data signal Es (dotted line)
and a second signal portion Bs (continuous thinner line) that is
part of, e.g., a receive signal. Here, the data signal Es has a
significantly lower frequency than the second signal portion Bs,
such that the bits of the second signal portion Bs are mounted on
the wave form of the data signal Es.
[0097] Thus, when comparing a receive signal Fs, which comprises
the second signal portion Bs and the data signal Es as components,
to the second signal portion Bs that has been used for generating
the transmit signal Cs, it can be inferred, when the second signal
portion Bs extracted from the receive signal Fs deviates from the
original second signal portion Bs, that the response signal Ds
emitted by the transponder has been interfered with, such that the
integrity of the data signal Es is also in question.
[0098] Here, detecting errors is in particular possible without
transmitting the data of the transponder and the data signal,
respectively, in a redundant manner. Thus, the energy requirements
of the transponder are reduced and the range between the
transponder (e.g. an RFID transponder) and the apparatus for
communication 1 (e.g. an RFID reader) is extended.
[0099] In further configurations, additional redundancies are added
to the raw data streams of data sources A, Bs and Es.
[0100] Although some aspects have been described in the context of
an apparatus, it is obvious that these aspects also represent a
description of the corresponding method, such that a block or
device of an apparatus also corresponds to a respective method step
or a feature of a method step. Analogously, aspects described in
the context of a method step also represent a description of a
corresponding block or detail or feature of a corresponding
apparatus. Some or all of the method steps may be performed by a
hardware apparatus (or using a hardware apparatus), such as a
microprocessor, a programmable computer or an electronic circuit.
In some embodiments, some or several of the most important method
steps may be performed by such an apparatus.
[0101] Depending on certain implementation requirements,
embodiments of the invention can be implemented in hardware or in
software. The implementation can be performed using a digital
storage medium, for example a floppy disk, a DVD, a Blu-Ray disc, a
CD, an ROM, a PROM, an EPROM, an EEPROM or a FLASH memory, a hard
drive or another magnetic or optical memory having electronically
readable control signals stored thereon, which cooperate or are
capable of cooperating with a programmable computer system such
that the respective method is performed. Therefore, the digital
storage medium may be computer readable.
[0102] Some embodiments according to the invention include a data
carrier comprising electronically readable control signals, which
are capable of cooperating with a programmable computer system,
such that one of the methods described herein is performed.
[0103] Generally, embodiments of the present invention can be
implemented as a computer program product with a program code, the
program code being operative for performing one of the methods when
the computer program product runs on a computer.
[0104] The program code may, for example, be stored on a machine
readable carrier.
[0105] Other embodiments comprise the computer program for
performing one of the methods described herein, wherein the
computer program is stored on a machine readable carrier. In other
words, an embodiment of the inventive method is, therefore, a
computer program comprising a program code for performing one of
the methods described herein, when the computer program runs on a
computer.
[0106] A further embodiment of the inventive methods is, therefore,
a data carrier (or a digital storage medium or a computer-readable
medium) comprising, recorded thereon, the computer program for
performing one of the methods described herein. The data carrier,
the digital storage medium, or the computer-readable medium are
typically tangible or non-volatile.
[0107] A further embodiment of the inventive method is, therefore,
a data stream or a sequence of signals representing the computer
program for performing one of the methods described herein. The
data stream or the sequence of signals may, for example, be
configured to be transferred via a data communication connection,
for example via the Internet.
[0108] A further embodiment comprises a processing means, for
example a computer, or a programmable logic device, configured to
or adapted to perform one of the methods described herein.
[0109] A further embodiment comprises a computer having installed
thereon the computer program for performing one of the methods
described herein.
[0110] A further embodiment in accordance with the invention
includes an apparatus or a system configured to transmit a computer
program for performing at least one of the methods described herein
to a receiver. The transmission may be electronic or optical, for
example. The receiver may be a computer, a mobile device, a memory
device or a similar device, for example. The apparatus or the
system may include a file server for transmitting the computer
program to the receiver, for example.
[0111] In some embodiments, a programmable logic device (for
example a field programmable gate array, FPGA) may be used to
perform some or all of the functionalities of the methods described
herein. In some embodiments, a field programmable gate array may
cooperate with a microprocessor in order to perform one of the
methods described herein. Generally, the methods are performed by
any hardware apparatus. This can be a universally applicable
hardware, such as a computer processor (CPU) or hardware specific
for the method, such as ASIC.
[0112] While this invention has been described in terms of several
advantageous embodiments, there are alterations, permutations, and
equivalents which fall within the scope of this invention. It
should also be noted that there are many alternative ways of
implementing the methods and compositions of the present invention.
It is therefore intended that the following appended claims be
interpreted as including all such alterations, permutations, and
equivalents as fall within the true spirit and scope of the present
invention.
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